1. Field of the Invention
The field of the invention relates to gaming devices, methods and systems which accumulate a progressive prize and award the same to one or more players upon occurrence of a trigger condition. More particularly it relates to gaming devices, methods and systems which accumulate a mystery progressive prize.
2. Background
Various types of gaming devices have been developed with features designed to captivate and maintain player interest. In general, a gaming machine allows a player to play a base game of chance in exchange for a wager. In pay to play (P2P) gaming the wager has value such as wagering currency or credits representing currency. For novelty or “entertainment only” play the wagers are fictitious credits having no redemption value. Las Vegas style slot machines are an example of P2P gaming devices. Depending on the outcome of the base game, the player may be entitled to an award which is awarded to the player by the gaming machine, normally in the form of currency or game credits. Gaming devices may include flashing displays, lighted displays or sound effects to capture a player's interest in a gaming device.
Many modern gaming devices incorporate a secondary, feature or bonus game. These secondary games may be triggered by one or more outcomes from the base game such as, for example, a predefined symbol combination. These types of triggers are sometimes referred to as symbol driven triggers since they are determined by base game symbols. When the symbol combination occurs the gaming device processor enables the display for play of a secondary game. The secondary game may take the form of a number of free plays of the base game, a random selection game where the player selects from displayed offerings to reveal prizes, the play of a secondary game or the like.
In addition to symbol driven triggers there is also known to provide mystery prizes to players over and above any awards from the play of the base game or any base game symbol triggered feature. Often these mystery prizes are progressive prizes which may be arranged in triggered in a variety of manners. For example, in Olive, U.S. Pat. No. 7,108,603 issued Sep. 19, 2006 and titled “Slot Machine Game and System with Improved Jackpot Feature” there is a disclosed networked gaming machines contributing, from the wagers for the play of the base games, to a progressive jackpot. Based upon the value of the wager W at a gaming device to play a base game and the predetermined turnover for the jackpot, virtual lottery is conducted (out of sight of the player) with each base game play where the odds of winning relate to the wager W and jackpot turnover amount. When the feature is triggered play of a feature game determines the size of the award based upon a score from the feature game. Torango, U.S. Pat. No. 6,592,460 issued Jul. 15, 2003 and titled “Progressive Wagering System” discloses a similar type of “hidden lottery” type of mystery prize. In Acres et al U.S. Reissued patent RE38,812, reissued Oct. 4, 2005 and titled Method and Apparatus for operating Networked Gaming Devices”, the disclosure of which is incorporated by reference, there is disclosed a system based mystery jackpot which is triggered when the progressive pool reaches a selected (and unrevealed) amount.
A drawback to these prior mystery award techniques is that they either simply award an amount as determined by the system and/or progressive controller, for example the amount of the progressive jackpot pool when the mystery is triggered or, provide for the play of a single feature game. For example, in Olive U.S. Pat. No. 7,108,603 when the feature is triggered the player plays a feature “spin and hold” game and based upon the score range a selected award is issued to the player.
It would be advantageous to provide a progressive prize which has a prize value PV when the prize is triggered, where the PV is awarded by a series of free game plays each play resulting in a random winning or losing outcome, awards for winning outcomes and an expected value (EV) and where the number of free plays at least approximates PV/EV. It would further be advantageous, where EV is not an aliquot of PV to provide a system, apparatus and method for accounting for any remainder of a fraction of free plays where EV is not an aliquot of PV. It would further be advantageous to provide one or more feature trigger types in such apparatus, systems and methods.